Definition

Leukemia is a cancer of the blood cells. Three main types of blood cells are:

• White blood cells (WBC), also called lymphocytes—help fight infections
• Red blood cells (RBC)—carry oxygen
• Platelets—help the blood clot at injury sites

The most common types of leukemia in children are:

• Acute lymphoblastic leukemia (ALL)
• Acute myeloid leukemia (AML)

White Blood Cells

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Causes

Leukemia starts in the bone marrow where blood cells are made. It happens when certain blood cells divide without control or order. The abnormal cells crowd out the healthy blood cells. This causes many of the symptoms.

The cause of leukemia is not clear. It is likely a combination of genes and environment.

Risk Factors

Things that may raise the risk of leukemia in children are:

• Exposure to certain chemicals, such as benzene
• High doses of radiation therapy
• Some chemotherapy drugs
• A sibling with leukemia—especially an identical twin
• Genetic conditions, such as:
  • Down syndrome, Li-Fraumeni syndrome, or Klinefelter syndrome
  • Wiskott-Aldrich syndrome, ataxia-telangiectasia, neurofibromatosis, or Fanconi anemia

Symptoms

Symptoms of leukemia may be:

• Feeling weak or tired
• Fever or night sweats
• Lack of hunger, and weight loss without trying
• Easy bleeding and bruising
• Problems breathing
• Pale skin, or tiny red spots under the skin
• Painless lumps in the neck, underarms, belly, or groin
• Pain in the bones or joints, or discomfort in the belly

Diagnosis

The doctor will ask about the child’s symptoms and health history. A physical exam will be done. The doctor will check for swelling of the liver, spleen, or lymph nodes.

Tests will be done to look for abnormal cells. They may include:

• Blood tests—to measure the number and type of blood cells
• Bone marrow biopsy —a sample of bone marrow is taken and tested for cancer cells
• Lumbar puncture —tests the fluid around the brain and spinal cord for cancer cells

If cancer cells are found, more tests may be done. These tests will check if and where any cancer has spread. Tests may include imaging, such as:

• CT scan
• X-ray
• Ultrasound
• MRI scan

Treatment

The goal for acute leukemia is to destroy cancer cells and return the blood and bone marrow to normal. Symptoms may need to be treated first. Treatment may include:

• Antibiotics to treat infections
• Blood transfusion—to treat severe anemia or bleeding

Treatment is based on the type of leukemia. One or more options may be used, such as:

• Chemotherapy by mouth, injection, or IV—to kill cancer cells
• Radiation therapy—to kill cancer cells
• Bone marrow transplant—an injection of healthy bone marrow, to make healthy blood cells
• Stem cell transplant—healthy immature blood cells are put in the blood
• Biological therapy—drugs that help the body fight the cancer
• Medicines to help manage treatment side effects

Prevention

There are no current guidelines to prevent leukemia in children.